Long Rotational Coherence Times of Molecules in a Magnetic Trap
Luke Caldwell, H. J. Williams, N. J. Fitch, J. Aldegunde, Jeremy M. Hutson, B. E. Sauer, M. R. Tarbutt
Abstract
Polar molecules in superpositions of rotational states exhibit long-range dipolar interactions, but maintaining their coherence in a trapped sample is a challenge. We present calculations that show many laser-coolable molecules have convenient rotational transitions that are exceptionally insensitive to magnetic fields. We verify this experimentally for CaF where we find a transition with sensitivity below 5 Hz G^{-1} and use it to demonstrate a rotational coherence time of 6.4(8) ms in a magnetic trap. Simulations suggest it is feasible to extend this to more than 1 s using a smaller cloud in a biased magnetic trap.
Topics & Concepts
Coherence (philosophical gambling strategy)Magnetic trapAtomic physicsDipolePhysicsTrap (plumbing)Magnetic fieldLaserChemical polarityMoleculeRotational transitionMagnetic dipolePolarMolecular physicsOpticsAngular momentumQuantum mechanicsMeteorologyCold Atom Physics and Bose-Einstein CondensatesAtomic and Subatomic Physics ResearchAdvanced Frequency and Time Standards